Agnès Festré & Pierre Garrouste

(GREDEG)

Vendredi 11 mars 2016

Résumé :In an ultimatum game are players’ decisions sensitive to the range of splitting strategies range? Is the role of an observer effective and does the payment scheme affect the observation effect? In order to answer those questions, we use a twofold manipulation in a one-shot anonymous ultimatum game with a limited number of division choices (in fact, two divisions: 20-80 and 80-20). On one hand, building upon the evidence found in the literature regarding behavior due to variations of the range of possible splitting strategies in bargaining games, we test whether the introduction of an “equal split” allocation option choice has an effect on offers and rejection rates. On the other hand, we introduce a third-party (called an “observer”), who is informed about the allocation decision and investigate its influence on the decisions of the two other parties. Surprisingly we find no effect of observation in the 20-80 and 80-20 division case. Furthermore, contrary to what was expected and to previous ‘comparable’ experiments by Falk, Fehr and Fischbacher (2003), adding the “equal split” allocation to the two initial division choices seems to have no significant impact on rejection rates of receivers. Most interesting, when the equal split option is added, we found that observation makes offers and rejection rates independent from each other. We conclude that observation plays the role of a substitute for a norm of fairness. Finally, we show that the payment scheme of the observer (fixed or variable) affects neither the proposer nor the responder’s decisions.